In the next two years more than 30 cities in Europe plan to install wireless Internet, or Wi-Fi, zones allowing people to surf the net and check their e-mail on the move. But is there a hidden health time bomb behind the Wi-Fi revolution? That is the question scientists in the U.K. are trying to answer as Europe's demand for wireless Internet continues to boom. Paul Burge reports for VOA News.

Walk down the street, into a coffee shop or even a school and you are bound to see people tapping away at laptops, invisibly connected to the Internet.

Wireless Fidelity, or Wi-Fi to use it’s a catchier name, allows users to access broadband Internet wherever a Wi-Fi signal is transmitted.

But some scientists have serious concerns about the effects of what they call an "electronic smog" from wireless networks that link computers to the worldwide web.

They say that living in a soup of electromagnetic radiation one billion times stronger than natural fields will cause severe long-term health problems.

There is particular concern about children. Wi-Fi skeptics say they are more vulnerable because their skulls are thinner and their nervous systems are still developing.

Research from Sweden claims that the radiation kills off brain cells, and that could lead to today's younger generation going senile in their 40s and 50s.

And schools are one place where Wi-Fi Internet has been extensively introduced. In the U.K., approximately half of primary schools and four-fifths of secondary schools use Wi-Fi Internet networks.

Philip Parkin is general secretary of the Professional Association of Teachers. He is asking for schools to consider very carefully whether they should be installing Wi-Fi networks. "My particular concerns are the effects on educational establishments, and the effects not only on staff -- because this issue started with problems of a member of a staff had who was one of our members -- but particularly now the issues relating to young children and the potential effects that Wi-Fi and exposure to electro magnetic radiation will have on young children."

William Stewart is the chairman of the Health Protection Agency and a former chief scientific adviser to the British government. He is privately pressing for an official investigation of the risks Wi-Fi may pose.

Yet, Britain's Health Protection Agency says there are no heath risks connected to the use of Wi-Fi networks. The agency says the frequencies used are the same as those from FM radio, TV and mobile phones. They add that there is no reason why schools should not use Wi-Fi equipment either.

There is no sign health concerns are slowing the wireless expansion. In the past 18 months 1.6 million Wi-Fi terminals have been sold in Britain for use in homes and offices.

Michael Snyder, who chairs the City of London's Policy & Resources Committee, wants a city-wide system. "People are very busy these days and instant access to communication networks, whether it's voice over Internet or their mailbox or the Internet for other information, is absolutely vital and this is a very modern and very effective way of giving that coverage."

And now the Wi-Fi wildfire is spreading across Europe, too. The research firm Gartner Dataquest says Wi-Fi users across Europe have surged from three million to 23 million over the last three years. And by 2008 it is estimated there will be 160 million Wi-Fi-enabled devices in Western Europe.